It is expected to map what displayed on a screen of a handheld terminal to a screen of a vehicle-mounted terminal, such that the driver can send a control instruction to the handheld terminal by touching the screen of the vehicle-mounted terminal, so as to synchronously manipulate the handheld terminal. To achieve this purpose, the vehicle-mounted terminal must know the orientation of the screen of the handheld terminal before synchronous manipulation. Otherwise, it is very likely that the touch coordinate would shift during the process of synchronous manipulation, which would greatly affect the effect of the synchronous manipulation.
In the related art, whether the screen is in a landscape orientation or in a portrait orientation is usually determined by calculating an average grayscale value of a screen shared image. However, in order to calculate the average grayscale value of the screen shared image, it is necessary to have prior knowledge of the mapping region onto which the screen of the handheld terminal is mapped on the screen of the vehicle-mounted terminal and it is necessary to calculate the average grayscale value of the whole non-mapping region. Therefore, the operation data amount is huge, and particularly when a night-scene image is displayed, the average grayscale value of the image itself is relatively low but brightness of the background color in the non-mapping region is relatively high, so accuracy of the identification result cannot be ensured.